[Ongoing] Rewrite frontend to use Flex/Bison

This is a merge of another experiment, so the changes are large:

- separated "modules" directory into frontend/backend
  - adjusted module names and moved files for this to happen
- removed modules lexer & parser
- removed all the unit tests (most were outdated)
- added Bison, flex, and C development tools to manifest.scm
- added lexer.l, a source file used by the flex utility with a functioning lexing implementation
- added parser.y, a source file used by the bison utility with a functioning parser implementation
- added node.c and node.h, which parser.y uses to construct an AST of a C source file (up to binary ops)
- added driver.c, a Guile-C interface that provides a module to scheme programs
- added a Makefile to make all of this
- added stuff to .gitignore

1 files changed, 3 insertions, 0 deletions

diff --git a/src/frontend/driver.scm b/src/frontend/driver.scm
new file mode 100644
index 0000000..402e6e9
--- /dev/null
+++ b/src/frontend/driver.scm
@@ -0,0 +1,3 @@
+(define-module (frontend driver))
+
+(load-extension "./libull.so" "scm_init_parser_driver_module")